As the value and use of information continues to increase, individuals and businesses continually seek additional ways to process and store information. One option available to users of information is an information handling system. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Information handling systems may be included as elements of a storage network. A storage network can be considered as a specialized network of storage devices coupled to one or more data servers. A storage enclosure is an element of a storage network. A storage enclosure is a self-contained physical enclosure that includes within the enclosure a number of storage elements or storage drives. Storage drives typically comprise disk-based hard drives. Today, many parallel SCSI storage enclosures have the ability to be split to create two separate SCSI buses, allowing two SCSI storage networks to share the same storage enclosure. In this configuration, each of the SCSI storage networks will include its own dedicated SCSI bus and generally half of the slots or storage drives of the storage enclosure. A configuration of this kind is possible in a parallel SCSI network because the SCSI bus within the storage enclosure can be physically or electrically split, thereby forming two separate SCSI domains. The SCSI bus of the parallel SCSI network of the storage enclosure can be divided by placing a mechanical disconnection in the storage enclosure or by electrically isolating the two SCSI buses by disabling the repeater or expanders along the length of the SCSI bus. The dividing of the SCSI bus creates separate SCSI domains.
Serial Attached SCSI (SAS) is a storage network interface and communications protocol for storage transactions. Serial Attached SCSI is characterized by storage networks having a serial, point-to-point architecture and improved data integrity, as compared with parallel SCSI storage networks. Because of the topology of an SAS storage network, separate SCSI domains cannot be created by dividing the SCSI bus of the storage enclosure, as buses are not present in an SAS architecture. Each storage drive of an SAS storage network is dual ported, and each storage drive can be coupled to two controllers of the enclosure. Because each drive can be coupled to each of the two controllers of the enclosure, each drive may be accessed through each of the two host ports coupled to the storage enclosure through the controllers of the storage enclosure.